Yeah, I said T's but I meant rails.

I've never had the issue.
I drained them every fall when I only had one, for a few years, then I thought, maybe that would promote the rubber drying out.
Then I swapped the jets to 38's and never did it again, just started treating the gas before putting them away.
I guess the reasoning is, draining them helps to prevent gumming up, but for 3 or 4 months at most, I don't know if it's needed.